homework/js_homework_09/main.js

// /////////////////////////makeProfileTimer
function makeProfileTimer() {
    let startTime = performance.now();
    return function () {
        return performance.now() - startTime;
    }
};
const timer = makeProfileTimer();

alert('Замеряем время работы этого alert');
alert(`Time for this alert running is: ${timer()}`);

// ////////////////////// makeSaver
function makeSaver(func) {
    let run1 = true;
    let saveResult;
    return function () {
        if (run1) {
            saveResult = func();
            run1 = false;
            console.log(`Result is saved: ${saveResult}`);
        }
        return saveResult;
    }
}

var saver = makeSaver(Math.random);

var value1 = saver();
var value2 = saver();
value1 === value2;

var saver2 = makeSaver(() => console.log('saved function called') || [null, undefined, false, '', 0, Math.random()][Math.ceil(Math.random() * 6)]);
var value3 = saver2();
var value4 = saver2();

value3 === value4;

// //////////////////////////Final Countdown
function finalCountdown() {
    for (let i = 0; i < 5; i++) {
        setTimeout(() => console.log(5 - i), 1000 * i)
    }
    setTimeout(() => console.log("поехали !"), 5000)
}

// ////////////////////////////myBind
function myBind(func, tempThis, tempArray) {
    return function (...arguments) {
        let i = 0;
        let newTempArray = tempArray.map((value) => (value === undefined ? arguments[i++] : value));

        return func.apply(tempThis, newTempArray); 
    };
}